Shape-Memory Microfluidics
Shape-Memory Microfluidics
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DOI：
10.1002/adfm.201203618
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发表时间：
2013-10-11
影响因子：
19
通讯作者：
Bettinger, Christopher J.
中科院分区：
文献类型：
--
作者：
Balasubramanian, Aditya;Morhard, Robert;Bettinger, Christopher J.
具有嵌入的血管网络的材料提供对本体材料性质的快速和增强的控制，包括温度调节和活性化合物如愈合剂或刺激物的分布。血管化材料在自愈合系统和组织工程结构中具有广泛的潜在应用。在这里，应用血管化材料的刺激响应微流体网络中的加速相变的报告。聚（酯酰胺）弹性体是吸湿性的，并表现出热机械性能（T-g约为37 ℃），其使得加热或水合能够用作刺激以诱导玻璃态-橡胶态转变。水化依赖的弹性作为刺激响应的形状记忆微流体网络的基础。在几种操作模式下测量形状记忆微流体的恢复动力学。与未灌注的装置相比，将刺激灌注辅助递送到形状记忆微流体的大体积显著加速形状恢复动力学。灌注和非灌注情况下的恢复时间分别为4.2 +/- 0.1 h和8.0 +/- 0.3 h。通过有限元模拟，可以准确地预测在各种刺激递送模式下操作的形状记忆微流体装置的恢复动力学。这项工作证明了血管化材料的效用作为一种策略，以减少扩散的特征长度尺度，从而加速刺激响应散装材料的驱动。
Materials with embedded vascular networks afford rapid and enhanced control over bulk material properties including thermoregulation and distribution of active compounds such as healing agents or stimuli. Vascularized materials have a wide range of potential applications in self-healing systems and tissue engineering constructs. Here, the application of vascularized materials for accelerated phase transitions in stimuli-responsive microfluidic networks is reported. Poly(ester amide) elastomers are hygroscopic and exhibit thermo-mechanical properties (T-g approximate to 37 degrees C) that enable heating or hydration to be used as stimuli to induce glassy-rubbery transitions. Hydration-dependent elasticity serves as the basis for stimuli-responsive shape-memory microfluidic networks. Recovery kinetics in shape-memory microfluidics are measured under several operating modes. Perfusion-assisted delivery of stimulus to the bulk volume of shape-memory microfluidics dramatically accelerates shape recovery kinetics compared to devices that are not perfused. The recovery times are 4.2 +/- 0.1 h and 8.0 +/- 0.3 h in the perfused and non-perfused cases, respectively. The recovery kinetics of the shape-memory microfluidic devices operating in various modes of stimuli delivery can be accurately predicted through finite element simulations. This work demonstrates the utility of vascularized materials as a strategy to reduce the characteristic length scale for diffusion, thereby accelerating the actuation of stimuli-responsive bulk materials.